scholarly journals Influence of the reinforcement corrosion on the bending moment capacity of reinforced concrete beams: a structural reliability approach

2014 ◽  
Vol 7 (3) ◽  
pp. 379-413
Author(s):  
E. A. P. Liberati ◽  
E. D. Leonel ◽  
C. G. Nogueira
Keyword(s):  
Reinforced Concrete ◽  
Structural Reliability ◽  
Concrete Structures ◽  
Bending Moment ◽  
Probability Of Failure ◽  
Reinforced Concrete Beams ◽  
Chloride Diffusion ◽  
Reinforced Concrete Structures ◽  
Moment Capacity ◽  
Major Factors

Reinforced concrete structures are, certainly, one of the most used types of structure around world. When it is located in non-aggressive environments, it respects, in general, the structural life predicted. Unless the structure be used improperly. However, the durability of these structures is strongly connected to degradation processes whose origin is environmental and/or functional. Among these processes, it is worth to mention those related to corrosion of reinforcements. The reinforcement's corrosion is directly related to the durability and safety of concrete structures. Moreover, the chlorides diffusion is recognized as one of major factors that triggers the corrosion. Therefore, at modelling accurately the chloride diffusion, the corrosion of reinforcements can be better evaluated. Consequently, design criteria can be more realistically proposed in order to assure safety and economy into reinforced concrete structures. Due to the inherent randomness present on chloride diffusion and corrosion, these phenomena can only be properly modelled considering probabilistic approaches. In this paper, the durability of a beam designed using the criteria proposed by ABNT NBR 6118:2003 [1] is assessed using probabilistic approaches. The corrosion time initiation is determined using Fick's diffusion law whereas Faraday's corrosion laws are adopted to model the steel loss. The probability of structural failure is determined using Monte Carlo simulation. The mentioned beam is analysed considering different failure scenarios in order to study the influence of water/cement ratio and environmental aggressiveness on the probability of failure. Based on these results, some remarks are performed considering NBR recommendations and the real probability of failure.

STIFFNESS OF REINFORCED CONCRETE STRUCTURES UNDER BENDING WITH TRANSVERSE AND LONGITUDINAL FORCES

2021 ◽  
Vol 98 (6) ◽  
pp. 5-19
Author(s):  
VL.I. KOLCHUNOV ◽  
◽  
O.I. AL-HASHIMI ◽  
M.V. PROTCHENKO ◽  
◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Concrete Structures ◽  
Bending Moment ◽  
Reinforced Concrete Structures ◽  
The Matrix ◽  
Local Shear ◽  
The Difference ◽  
Inclined Cracks ◽  
Opening Width

The authors developed a model for single reinforced concrete strips in block wedge and arches between inclined cracks and approximated rectangular cross-sections using small squares in matrix elements. From the analysis of the works of N.I. Karpenko and S.N. Karpenko the "nagel" forces in the longitudinal tensile reinforcement and crack slip , as a function of the opening width and concrete deformations in relation to the cosine of the angle . The experimental " nagel " forces and crack slip dependences for the connection between and in the form of an exponent for the reinforcement deformations and spacing are determined. The forces have been calculated for two to three cross-sections (single composite strips) of reinforced concrete structures. On the bases of accepted hypothesis, a new effect of reinforced concrete and a joint modulus in a strip of composite single local shear zone for the difference of mean relative linear and angular deformations of mutual displacements of concrete (or reinforcement) are developed. The hypothesis allows one to reduce the order of the system of differential equations of Rzhanitsyn and to obtain in each joint the total angular deformations of concrete and the "nagel" effect of reinforcement. The curvature of the composite bars has a relationship from the total bending moment of the bars to the sum of the rigidities. The stiffness physical characteristics of the matrix from the compressed concrete area and the working reinforcement are obtained in a system of equations of equilibrium and deformation, as well as physical equations.

Research on Parameters of RC Structure Reliability

2014 ◽  
Vol 501-504 ◽  
pp. 1061-1064
Author(s):  
Bin Cai ◽  
Xin Hui Liu
Keyword(s):  
Reinforced Concrete ◽  
Structural Reliability ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Engineering Structures ◽  
Reliability Design ◽  
Structure Reliability ◽  
Rc Structure ◽  
Practical Engineering ◽  
Materials Used

In the analysis of engineering structures are usually adopt the method of fixed value, that is the practical engineering structure under load and the performance of materials used by structure shall be treated as a constant value.But, in fact, the structure of geometry size, bear the load, material parameters,computing model and so on are affected by various factors. In order to more accurately reflect the reliability problems of reinforced concrete structures, this paper, the factors above will be regarded as random variables, combining the basic theory of reliability design, through the probability analysis, in normal uselimit state reliability of reinforced concrete structures for example analysis of the influence of related parameters on the structural reliability.

Non-Destructive Vibration Tests on Reinforced Concrete Structures

2015 ◽  
Vol 660 ◽  
pp. 186-191 ◽  
Author(s):  
Marina Lute
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Response ◽  
Concrete Beams ◽  
Concrete Structures ◽  
Reinforced Concrete Beams ◽  
Reinforced Concrete Structures ◽  
Linear Behavior ◽  
Non Linear ◽  
Vibration Tests ◽  
Non Destructive

The purpose of this paper is looking at the dynamic response of existing reinforced concrete structures which have possibly sustained various levels of damage, a set of tests need to be identified that will be able to detect damage and quantify the damage if damage exists. In this work it is presented a further study on the effect of damage on the behavior of reinforced concrete beams. In particular, the non-linear behavior of these beams is considered once significant cracking has been introduced, outlining the stage of testing carried out in dynamic field.

scholarly journals Calculation of damage RC constructions according to deformation model

2020 ◽  
Vol 2020 (2) ◽  
pp. 99-106
Author(s):  
Yaroslav Blikharskyy ◽  
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Concrete Structures ◽  
Physical And Mechanical Properties ◽  
Reinforced Concrete Beams ◽  
Core Material ◽  
Deformation Model ◽  
Reinforced Concrete Structures ◽  
The Impact

This article presents results of a theoretical study of reinforced concrete beams with damaged reinforcement. The change of micro-hardness of a reinforcing rebar’s with a diameter of 20 mm of A500C steel in the radial direction is investigated and the thickness of the heat-strengthened layer is established. It is established that the thickness of the thermo-strengthened steel layer of the reinforcing bar with a diameter of 20 mm of A500C is approximately 3 mm. It is shown that the strength characteristics of this layer are on 50% higher compared to the core material of the rebar, while the plasticity characteristics are lower. The aim of the work is to determine the strength and deformability of reinforced concrete structures without damaging the reinforcement and in case of damage. Determining the impact of changes in the physical characteristics of reinforcement on the damage of reinforced concrete structures, according to the calculation to the valid norms, in accordance with the deformation model. To achieve the goal of the work, theoretical calculations of reinforced concrete beams were performed according to the deformation model, according to valid norms. This technique uses nonlinear strain diagrams of concrete and rebar and is based on an iterative method. According to the research program 3 beam samples were calculated. Among them were undamaged control sample with single load bearing reinforcement of ∅20 mm diameter – BC-1; sample with ∅20 mm reinforcement with damages about 40% without changes in the physical and mechanical properties of reinforcement – BD-2 and sample with ∅20 mm reinforcement with damages about 40% with changes in the physical and mechanical properties of reinforcement – BD-3. The influence of change of physical and mechanical characteristics of rebar’s on bearing capacity of the damaged reinforced concrete beams is established.

scholarly journals THE PROPERTIES OF PITTING CORROSION OF STEEL REINFORCEMENT OF REINFORCED CONCRETE BEAMS

2017 ◽  
Vol 2 (3) ◽  
pp. 32-36
Author(s):  
Дронов ◽  
Andrey Dronov
Keyword(s):  
Reinforced Concrete ◽  
Pitting Corrosion ◽  
Concrete Beams ◽  
Concrete Structures ◽  
Steel Reinforcement ◽  
Reinforced Concrete Beams ◽  
Reinforced Concrete Structures ◽  
Damage Distribution ◽  
Chloride Environment ◽  
Corrosion Of Steel

Two types of steel reinforcement depassivation process: carbonation of concrete and chloride penetration are considered in the article. The comparison between the corrosion due to carbonation of concrete and the chloride-induced corrosion was carried out. It was found out, that chlorides induced corrosion is potentially more dangerous than that resulting from carbonation. Method of durable tests of reinforced concrete structures under the action of the gravitational load and the corrosive chloride environment is described in the article. The results of experimental research on reinforced concrete structures with corrosive damages to steel reinforcement are given in the article. The properties of corrosion cracking in the case of the pitting corrosion were determined. The character of corrosive damage distribution along the reinforcement bars and its effect on the strength of reinforced concrete beams were determined.

THE INFLUENCE OF BASALT-COMPOSITE PRESTRESSED REINFORCEMENT ON THE OPERATION OF LOW-REINFORCED CONCRETE STRUCTURES WITH INTERBLOCK CONSTRUCTION JOINTS

2020 ◽  
pp. 50-59
Author(s):  
O.D. RUBIN ◽  
◽  
S.E. LISICHKIN ◽  
O.V. ZYUZINA
Keyword(s):  
Reinforced Concrete ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Bending Moment ◽  
Reinforced Concrete Beam ◽  
Hydraulic Structures ◽  
Reinforced Concrete Structures ◽  
Beam Type ◽  
Construction Joints ◽  
Composite Reinforcement

It is proposed to use prestressed basalt composite reinforcement to strengthen reinforced concrete structures of hydraulic structures. In order to substantiate technical reinforcement of reinforced concrete structures of hydraulic structures with prestressed basalt composite inforcement, experimental studies were carried out. For experimental studies, reinforced concrete beam-type structures with vertical interblock construction joints were adopted.The results of experimental studies of reinforced concrete models of beam type with interblock joints reinforced with prestressed basalt composite reinforcement by the method of tension “on concrete”are presented. The models are tested for bending moment and transverse force. A special character of cracking is noted; full restoration of the bearing capacity of reinforced concrete structures, weakened by interblock construction joints, was recorded due to the reinforcement of prestressed basalt composite reinforcement.

A new method for estimating the scale of fluctuation in reliability assessment of reinforced concrete structures considering spatial variability

2018 ◽  
Vol 21 (13) ◽  
pp. 1951-1962 ◽  
Author(s):  
Yiming Yang ◽  
Jianxin Peng ◽  
Jianren Zhang ◽  
CS Cai
Keyword(s):  
Reinforced Concrete ◽  
Spatial Variability ◽  
Bayesian Information Criterion ◽  
Concrete Structures ◽  
Estimation Method ◽  
Bending Moment ◽  
Information Criterion ◽  
Geometrical Parameters ◽  
Reinforced Concrete Structures ◽  
Scale Of Fluctuation

The scale of fluctuation ( θ) of the material and geometrical parameters is the basis of studying the spatial variability of reinforced concrete structures. In this article, a new estimation method for the scale of fluctuation based on Bayesian information criterion is proposed. And based on the analysis of experimental data recorded on the three 36-year-old beams of the Jianggong Bridge and 246 corroded steel bars, the scale of fluctuation ( θ) of concrete compressive strength ( fc) and steel pitting factor ( R) are estimated. The theoretical bending moment of three test beams are calculated considering the influence of the spatial distributions of fc, R, and other relative variables. The reasonableness and superiority of the Bayesian information criterion model than the auto-correlation function method and the semivariogram function model are verified by comparing the theoretical results with the measured bending moment of the three beams mentioned above.

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